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Date:   Thu, 27 Oct 2022 08:01:52 +0000
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From:   "Yajun Deng" <yajun.deng@linux.dev>
Message-ID: <d57108689d0ab40cf6e51829bb938a2b@linux.dev>
Subject: Re: [PATCH] sched/fair: Remove max_vruntime() and min_vruntime()
To:     "Peter Zijlstra" <peterz@infradead.org>
Cc:     mingo@redhat.com, juri.lelli@redhat.com,
        vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
        rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de,
        bristot@redhat.com, vschneid@redhat.com,
        linux-kernel@vger.kernel.org
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 <20221027015351.2511149-1-yajun.deng@linux.dev>
 <Y1o5ILxBd9erW5zR@hirez.programming.kicks-ass.net>
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October 27, 2022 3:55 PM, "Peter Zijlstra" <peterz@infradead.org> wrote:=
=0A=0A> On Thu, Oct 27, 2022 at 09:54:09AM +0200, Peter Zijlstra wrote:=
=0A> =0A>> On Thu, Oct 27, 2022 at 09:53:51AM +0800, Yajun Deng wrote:=0A=
>> There is no need to write max_vruntime() and min_vruntime() functions,=
=0A>> we can use max_t() and min_t() instead.=0A>> =0A>> Here; I did your=
 homework for you:=0A>> =0A=0AThanks for your guidance.=0A=0A>> /* max.c =
*/=0A>> #include <stdio.h>=0A>> #include <stdint.h>=0A>> #include <stdlib=
.h>=0A>> =0A>> typedef unsigned long long u64;=0A>> typedef unsigned long=
 long s64;=0A> =0A> This should obviously be just 'long long', but the re=
sult doesn't=0A> change.=0A> =0A> /me goes goes get more wake-up juice.=
=0A> =0A>> static u64 max_vruntime(u64 max_vruntime, u64 vruntime)=0A>> {=
=0A>> s64 delta =3D (s64)(vruntime - max_vruntime);=0A>> if (delta > 0)=
=0A>> max_vruntime =3D vruntime;=0A>> return max_vruntime;=0A>> }=0A>> =
=0A>> static u64 max(u64 a, u64 b)=0A>> {=0A>> return a > b ? a : b;=0A>>=
 }=0A>> =0A>> int main(int argc, char **argv)=0A>> {=0A>> u64 a, b;=0A>> =
=0A>> if (argc < 3)=0A>> return 0;=0A>> =0A>> a =3D strtoll(argv[1], NULL=
, 10);=0A>> b =3D strtoll(argv[2], NULL, 10);=0A>> printf(" max(%lu, %lu)=
 =3D %lu\n", a, b, max(a,b));=0A>> printf("max_vruntime(%lu, %lu) =3D %lu=
\n", a, b, max_vruntime(a,b));=0A>> =0A>> return 0;=0A>> }=0A>> =0A>> $ .=
/max -1 0=0A>> max(18446744073709551615, 0) =3D 18446744073709551615=0A>>=
 max_vruntime(18446744073709551615, 0) =3D=200